Generate several scene from files (csv, yml with parameters) and thus, initialize the scene before loading a file.


In my code, I am creating a plane(object mode) and want to subdivide it (edit mode). Yet I have this error message:

RuntimeError: Operator bpy.ops.object.editmode_toggle.poll() failed, context is incorrect

can anyone has a solution?

Info: before toggle to edit mode, I select and activate the plane and on my Blender GUI, the plane seems to be in Edit mode (with the vertices visible) yet I am still in object mode 😕


It seems that it come from the bpy.ops.wm.read_homefile()..

@rob: I made a little addons that you can place in a directory "test_addons" in the scripts/addons. This show how you cannot (?) use


with a toggle_mode right after...

__ init__.py

bl_info = {
    "name": "Test Addons",
    "author": "",
    "location": "View3D > Tools > Test_addons",
    "version": (1, 0, 0),
    "blender": (2, 7, 9),
    "description": " ",
    "wiki_url": "",
    "category": "Development"

if "bpy" in locals():
    import importlib

    import bpy
    from bpy.types import PropertyGroup
    from bpy.props import (PointerProperty, FloatProperty)
    from . import ui
    from . import new_plane 

class MyPlane(PropertyGroup): 

    size = FloatProperty(name="Size", default=5., min=0, max=100,)

classes = (ui.NewToolBar, new_plane.NewPlane, MyPlane)

def register():
    for cls in classes:     
    bpy.types.Scene.my_plane = PointerProperty(type=MyPlane)


import bpy
from bpy.types import Panel

class NewToolBar(Panel):
    bl_category = "test_addons"
    bl_label = "test_addons"
    bl_region_type = "TOOLS"
    bl_space_type = "VIEW_3D"
    bl_context = "objectmode"

    def draw(self, context):                
        self.layout.operator("my_plane.new", text="New Plane")


import bpy
from bpy.types import Operator

class NewPlane(Operator): 
    bl_idname = "my_plane.new"
    bl_label = "My Plane"
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self, context): 

        # I load the home file

        # create an object and change its mesh in EDIT mode : I have an error message...
        my_plane = bpy.context.scene.my_plane
        bpy.ops.mesh.primitive_plane_add(radius=my_plane.size, location=(0., 0., 0.))

        return {'FINISHED'}

Error message

File "C:\Blender\2.79\scripts\modules\bpy\ops.py", line 189, in __call__
ret = op_call(self.idname_py(), None, kw)
RuntimeError: Operator bpy.ops.object.mode_set.poll() failed, context is incorrect
  • $\begingroup$ can you post the code? then we can try and replicate the issue. $\endgroup$ – rob Jul 31 '18 at 9:50
  • $\begingroup$ If you want to be in a certain mode I'd recommend testing context.mode and using bpy.ops.object.mode_set(mode='EDIT') As mentioned posting code, and how and where you are running it will give more context to q. $\endgroup$ – batFINGER Jul 31 '18 at 10:20
  • $\begingroup$ Would strongly reconsider the use of read homefile in an operator like above. The context gets trashed after the call. Would trash anything in the file too, doubt there would be any undo available.... $\endgroup$ – batFINGER Aug 2 '18 at 11:11
  • $\begingroup$ Actually, I did reconsider it now as I found out that I would have this issue... The goal I have is to generate several scene from a set of file. Thus I need to initialize the scene before creating a new one (or delete everything). I am still wondering if there is a nice way to do it ! $\endgroup$ – Mathou Aug 2 '18 at 11:14
  • 1
    $\begingroup$ The elephant in the room is 2.8. eg see the write-up re templates $\endgroup$ – batFINGER Aug 2 '18 at 14:36

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